Pathwork Diagnostics is betting a new study that examined the impact of its array-based tissue-of-origin test on the treatment and survival of patients with cancer of unknown primary will spur interest in the test among clinicians and payers.
Working together with collaborators at Cedar Associates, Stanford University, Memorial University of Newfoundland, and the University of Washington, Pathwork was able to show that the use of its test to guide treatment regimens ultimately resulted in longer periods of survival for CUP patients at a cost considered to be lower than the threshold for cost-effectiveness in the US.
The team will present the data from the study later this week at a lung cancer conference in San Diego sponsored by the American Association for Cancer Research and the International Association for the Study of Lung Cancer.
Shawn Becker, vice president of marketing and reimbursement for Pathwork, said that the study is significant for the firm for several reasons. For one thing, he said, the TOO test caused the use of chemotherapy regimens consistent with guidelines for the final tumor-site diagnosis to increase from 42 percent of cases to 65 percent of cases.
Moreover, the projected increase in survival rose from 15.9 months to 19.5 months, a mean gain of 3.6 months overall survival, Becker said. Also, Becker said that the new study shows the TOO test's cost effectiveness, with an average cost per quality-adjusted life year gained of $46,858 — below the accepted cost-effectiveness cutoff of $100,000.
"Most significantly, it is our first health economics study, which will resonate with providers and payers who in today’s environment are increasingly focused on cost effectiveness," Becker told BioArray News this week. "It shows [that] Pathwork Diagnostics can compete in an increasingly cost-focused environment, even with advanced molecular diagnostic technologies."
Based in Redwood City, Calif., Pathwork received US Food and Drug Administration clearance for the TOO test for use with frozen tissue samples in 2008 and formalin-fixed, paraffin-embedded samples in 2010 (BAN 6/15/2010).The chip used in the test is a custom array manufactured by Affymetrix and compares the expression of more than 1,500 genes in a tumor sample against 15 known tissues that represent more than 60 morphologies in order to identify the source of difficult-to-classify cancers and increase oncologists' confidence in their treatment approaches.
The test, which is offered as a service through Pathwork's CLIA-compliant lab, has been the focus of a number of publications in recent months. In May, a group of researchers published a study in which they evaluated the test on 49 malignancies (BAN 6/14/2011). Another paper, which appeared last month, detailed the performance of the test on 43 poorly differentiated and undifferentiated tumor samples (BAN 1/3/2012).
Pathwork's Becker said that the most recent study is currently being reviewed for publication. Also, Pathwork has "more studies underway demonstrating clinical utility and health outcomes including survival."
The Study
In a statement this week, John Hornberger, CEO of Cedar Associates and principal investigator on the new study, claimed that the test has "significantly altered clinical practice patterns for treating metastatic cancer."
Hornberger led the retrospective, observational study, which examined treatment changes made in patients by physicians who received test results. Changes in planned chemotherapy, surgery, radiation therapy, blood tests, imaging, and referral to hospice care before and after test results were recorded, according to Pathwork.
Estimates of the effect of changes in chemotherapy on survival were based on guidelines from the National Comprehensive Cancer Network and other treatment guidelines, while costs were estimated based on data from NCCN and Centers for Medicare and Medicaid Services fee schedules.
Changes in overall survival, costs, and cost per quality-adjusted life year gained were also estimated. QALY estimates the dollar value of a medical intervention, based on the number of years of life that would be added by the intervention, taking into account both the quality and the quantity of life lived.
Along with the increase in chemotherapy regimens and overall survival rates, the investigators also estimated the average increase in survival adjusted for quality of life to be 2.7 months, and said that average third-party payer costs per patient increased by $10,360.
The investigators concluded that Pathwork's TOO test "significantly altered clinical practice patterns for treating metastatic cancer of uncertain primary," and projected that the test could "increase overall survival, QALYs, and costs, resulting in an expected cost per QALY of less than $50,000."
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